The present invention relates to a method for selecting a mode of operation for at least two modems that communicate via a communications network. Furthermore, the invention relates to a modem unit adapted for transmitting data via a communications network.
The present disclosure refers to the following recommendations, standards, drafts and contributions, the subject matter of which is expressly incorporated herein by reference in their entirety as if fully set forth:    [G.992.1] Recommendation G.992.1 (formerly known as G.dmt), entitled “Asymmetrical Digital Subscriber Line (ADSL) Transceivers”, published in June 1999 by the International Telecommunication Union.    [G.992.2] Recommendation G.992.2 (formerly known as G.lite), entitled “Splitterless Asymmetrical Digital Subscriber Line (ADSL) Transceivers”, published in June 1999 by the International Telecommunication Union.    [G.992.3] Recommendation G.992.3, entitled “Asymmetric Digital Subscriber Line (ADSL) Transceivers-2 (ADSL2)”, published by the International Telecommunication Union.    [G.992.4] Recommendation G.992.4, entitled “Splitterless Asymmetric Digital Subscriber Line Transceivers-2 (Splitterless ADSL2)”, published by the International Telecommunication Union.    [G.992.5] Recommendation G.992.5, entitled “Asymmetric Digital Subscriber Line (ADSL) Transceivers—Extended Bandwidth ADSL2 (ADSL2+)”, published by the International Telecommunication Union.    [G.994.1] Recommendation G.994.1, entitled “Handshake Procedures For Digital Subscriber Line (DSL) Transceivers”, published in June 1999 by the International Telecommunication Union.
Most homes and businesses are connected to telephone networks using twisted pair copper wires. Until recently, these wires were used to carry data traffic in the analogue voice band. However, with the advancement of technology, particularly Digital Subscriber Line (DSL) technology, the transfer of data over the higher frequencies in the twisted pair copper wires is becoming more prevalent. The greatest advantage of DSL is that it enables data to be exchanged over the twisted pair copper wires at much higher speeds than conventional modems and analogue lines. The present invention is not limited to xDSL protocol standards.
Modem units that communicate via a communications network are initialized to a common mode of operation. The mode of operation might e.g. be an xDSL mode of operation, or a mode of operation according to any other protocol standard. If several different modes of operation are supported by the modem units, the best performance will be obtained by selecting a most suitable mode of operation.